It seems that some people are stamped on the forehead with the word "doctor" or "teacher" at birth and never stray from that career path. For many of us, however, finding our calling can involve a bit of trial and error. If you've taken a wrong turn and found yourself in a career backwater, joining a graduate training programme can be a good way of starting over. But, according to research by the Association of Graduate Recruiters, over 50% of graduates already in work are unaware that this option is open to them, as they mistakenly believe that only those who have just finished university are eligible.

"That these schemes are open to less recent graduates often isn't writ large enough in employers' recruitment literature," says Carl Gilleard, the association's chief executive. "But now employers are waking up to the fact they need to look beyond campus recruitment, as there are many talented people who don't follow the traditional route of going to university before getting a graduate job."

This is good news if you want to make a fresh start. But isn't it going to be tough competing against all those shiny, new graduates? And isn't there a danger that employers will see you as feckless if your employment history is perhaps a little chequered? That's not always the case, says Hannah Slaney, graduate programme manager with the Co-operative Group. "We're more interested in a person's capabilities and we often find trainees with a few years of work experience behind them stand out. They hit the ground running and have more credibility with those they manage. Also, they've often thought long and hard about what they want out of a job and so show a lot of commitment to the organisation."

Florence Cole, 25, a trainee on the Co-op's graduate development programme, is a case in point. After graduating in philosophy from Durham University in 2003, she was unsure of the direction she wanted to take. "I knew I wanted a job where I could make a difference and that was in keeping with my own ethical standards, but I wasn't exactly sure what that job was," she says.

Cole soon began temping for Barclays as a customer services adviser. Although it wasn't a graduate-level position, she feels it gave her valuable experience. "It was useful to see what it was like to be in a business environment where I was dealing with corporate clients and helping to meet customer needs. It definitely contributed to my development," she says.

Despite being taken on permanently, Cole didn't feel as if her future lay with Barclays, and her experience as a volunteer with Barnardo's led her to explore the possibility of a career in social care. She spent the next year as a residential support worker in a local authority children's home.

"The experimentation taught me what I didn't want to do as much as what I did," she says. "I came to the conclusion that I wanted a more structured development programme where I was working towards challenging targets, but in a business that fits with my own values and principles. I did some research and found that the Co-op scheme ticked all the boxes. By that time, I was ready for it. I had gained confidence in the world of work and come to a better understanding of what I had to offer. I'm definitely a more rounded person than I was three years ago."

Presenting your varied experience in the right way is the key to a successful application, says David Hammond who, at 31, is a graduate trainee with Nationwide. His first degree was in archaeology and, after a period of voluntary work, he spent a year on the Department for Work and Pensions' graduate scheme before deciding it wasn't for him. He then studied for an MA in the hope of continuing to a PhD and an academic career, but applied to the Nationwide programme when no funding was available for his doctorate.

"You do worry that you might appear unfocused," he says. "But you can always find a thread that runs through the different things you've done. You have to be able to emphasise that and explain your reasons for the route you have taken."

Cole feels that her disparate experience gave her the edge when it came to the selection process. "It's all about displaying competencies and I had plenty of real examples to draw on," she says. "Also, I was able to use my ongoing volunteer work as evidence that I was able to make a long-term commitment to something."

Those who worry they're simply too old to join a scheme should relax: age is no longer a barrier. Although some stipulate that you must have graduated within, for example, the last five years, many employers are now reviewing these policies in light of the age discrimination legislation introduced last year. But it's not all plain sailing for many older graduate trainees, as embarking on a programme may involve big sacrifices. It can mean a significant drop in pay, and you may need to be mobile. Hammond has two children and is now juggling his traineeship with his parenting responsibilities.

"Luckily my partner is very understanding and supportive," he says. "Nationwide has also been considerate of my family role, allowing me the flexibility to arrange my hours so that I can make it home on Friday evening."

And what's it like starting at the same level as other trainees who may be quite a bit younger - in Hammond's case, almost 10 years younger? "Sometimes I can't help thinking that if I'd been doing this a few years ago, I'd be well on my way by now," he says. "But I'm not someone who's just motivated by the idea of promotion after promotion. I'm happy that I'm in an organisation where I can develop and contribute. And if I'd come in straight from university, I'd have missed out on doing a lot of things that have given me personal fulfilment."